The invention relates to a current/charge leakage balancing device for display panel and, more particularly, a device that can eliminate and balance the residual charges between the lamps of the display panel module and the external metallic shield.
A display device such as a liquid crystal display device is usually provided with a backlight radiating source formed by a plurality of lamps. As illustrated in FIG. 1, Rs1/Rs2 are linear resistors (not necessarily identical). Meanwhile, C1, C2 are the principal equivalent stray capacitors of the lamps (not necessarily identical). Due to several factors such as fabrication factors, structure factors, or wiring factors, C1 and C2 usually are not balanced. Rx1, Rx2 represent the serial resistors of the equivalent stray capacitors. Because the backlight lamps usually need high frequency, high-voltage supply inverter, the equivalent circuit corresponding to the stray parasitic effects becomes more complex, and does not provide uniform and balanced allocation. The lamp currents that respectively pass through L1, L2 therefore are not uniform due to the parasitic effects. As a result, the brightness and the gray scale of the display panel are not uniform and balanced, which not only alters the display quality, but also may undesirably affect the user""s sight.
It is therefore an object of the invention to provide a waveform signal generator that can overcome the above disadvantages, and eliminate and balance the residual current and charges of the display panel.
To achieve the above and other objectives, the waveform signal generator of the invention is connected, either directly or through a cross-link element, to an external metallic shield of the display panel or a central layer of plastics. The waveform signal generator injects a signal to the central layer of plastics so as to eliminate and balance the residual current and charge of the display panel.
To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention.